1. Field of the Invention
The present invention relates to a speed control valve and in particular to a valve in which the operation is dampened so as to prevent sudden changes in flow rate and undesired oscillations.
2. The Prior Art
The use of speed control valves in hydraulic systems is well known in the prior art. However, the main drawback in the known valves is that the great speed in which they react to a change in fluid velocity may lead to their own self-destruction, due to the high impact created when the valve changes condition. When there is a sudden change in the velocity of the fluid passing through the valve, there is an almost immediate reaction with the valve changing condition. Thus, the valve may be actuated at an unwanted time by a momentary change and in so doing set up an undesired pattern of oscillations in the system.
The present invention overcomes the difficulties in the prior art by providing dampening of the movable valve element in either direction so that momentary fluid velocity changes will not trigger the valve and that operation will be controlled in such manner as to prevent damage to the valve itself.